Removable tread block



NOV. 14, KVB, KILBORN REMOVABLE TREAD BLOCK Filed Oct. 4, 1941 I A QQ 2] Lf Fly] L3 i .2/

,Patented Nov. 14, 1944 'REMovABLE TREAD-BLocK Kai-IAB. Killiorn, Akron, hio,zassignor.to Wing- 'foot Corporation, Akron, Ohio, a corporation of Delaware Application ctober 4, 1941, Serial No. 413,629

5 Claims.

Thisinvention relates toacontinuous track for a track laying vehicle. Moreparticularly .itxrelates to `a removable tread block for suchV a track and the means for assembling the ltread block ontothe track.

The usual typeof continuous track for amilitary vehicle or farmtractor orother farm vehicle or steam shovel or the like,l in which theztrack is self-laid, is made `up of `a cable Wound in helical form parallel to the length ofthe track and the cable is held between clamping `plates whichare coated on the top and ,bottom with rubber. The clamping plates are evenly spaced, and it is customary .to fasten a removable `tread blockto each pair of .clampingplates The tread blocks arebolted tothe clampingrplates at each end and at .the middle. The rniddlebolt ,isintegral With orfastened into .the .tread block. This` bolt, by means of .its head orsimilar typedevice, serves to hold the block to: the continuous bandv track. The shankof this `bolt isnsedfor holdingv ,and `at taching the guides wihichkeep the track centered on the driving sprockets, wheels, etc.

One dilliculty with a construction `of `this sort has been ,the :awkwardness of removing the nut from the centralbolt when replacing the removable tread. I I y According to this invention the removable tread is not. bolted. atthe. center to the track, but the upper surface of the removable tread is designed so that the tread is driven by the head of the center bolt used for fastening the sprocket guides, A

but without the tread being bolted to the track by this center bolt. This bolt is in no way integral with the tread block but may fit into the tread block after assembly of the tread block to the track. In this way the driving force of the sprocket is transmitted to the center of each removable tread, and almost directly, but the tread block may be removed and replaced without removing the center bolt or guides.

The removable treads are each composed of a metal Shoe to which therubber tread is vulcanized. In order to have the tread in driving relation with the bolt an opening may be provided in the shoe into which the bolt head fits; or an area of the shoe may be depressed to receive the bolt head; or a rib may be provided on the shoe against which the bolt head will press. Any such means for imparting the driving force of the vehicle to the center of the removable tread may be used.

The improved tread of this invention is bolted to the continuous track only at its outer ends. This makes it easily removable, and the driving force from the driving sprocketis :transmittedzto the center or any other suitablepart vof..tl'1e;.:e movable `tread by some such means as d'escrbed.

The invention will be further .describedxncqnnection with the accompanying drawinginwhich Fig. 1 is a vertical section through a removable tread at the lateral center of the clampingcplates; Fig. 2 is a section on the line 2:-2pfFg. 1;an'd Fig. 3`is a plan view of .a central portion ofi the track. The drawing shows the Acable4 Iv whichis wound helically the length of the ;.continu0us track and is clampedbetween thel upper clamping plate 2 and the lower clamping plate-.3 atregular intervals. The rubber "track 4 for the vbogie wheels is vulcanized to the upper'surface of the upper plate 2, and a cushion of rubber 5 is fastened or adhered to the lower surface of the lower plate. The under plate3-isgpedestaled at-6.

.As shown injFig. 2 the treadt-block is-'coxnposed of the shoe I0 and therubber tread II. The tread is` grooved across the center to `give better traction, as shown in Fig. 2. Theshoe-is anged at both sides and is alsoflangedaround the hole atthe center. The hanged hole provides a depression in the upper face of the shoe. This latter flange I2 forms arelatively tight-fitting pocketfor the head I3-of the bolt I4 orother projection from the lower clamping plate which holdsv the sprocket ,guides YI5 to the `continuous track.

As shown in Fig. 1 the head I3 of the bolt I4 preferably passes all the way through the metal shoe IU and Ais countersunk into the tread rubber I I. If preferred the shoe need not be punctured but may be shaped to t the bolt head I3, or

there may be a slight clearance between the bolt head and Irubber. The shoe I0 is preferably ribbed longitudinally to strengthen lt.

The sprocket guides I5 are of the usual design and overlap in the usual way. They'are fastened ilrrnly4 to the clamping plates 2 and 3 by the bolt I4. At each side of the upper clamping plate at the longitudinal center of the track is a lip I 6 against which the driving sprocket presses in driving the track. I1 is the base portion of the sprocket guides to which the wings I5 are attached.

The removable tread block is held to the track by the bolts 20. The shoe I0 is ilush against the pedestals 6 on the lower clamping plates 3 at -1 that they do not extend beyond the heads. In the preferred form of the invention the bolts 20 are held in place While-the tread I'I is vulcanized to the shoe, andthe tread is simultaneously Vulcanized over the head 2| of the bolt 20 and holds this bolt in place.

In use, the tread blocks wear down, and occasionally a large chunk of rubber is torn away from one of the blocks. It is therefore necessary to replace vthese blocks from time to time. The present track and removable tread blocks are so designed that any one or more tread blocks may be very easily removed from the continuous tracks.

When it becomes necessary to replace a tread block the nuts 22 at each end of the tread block are loosened, and the shoe l0 with the tread Il is removed by slipping the bolts 20 out of the bolt holes at the ends of the clamping plates. A new tread block is then put in place and is secured merely by tightening the nuts 22. f

Thetrack is driven by a sprocket which straddles the bolt I4 and presses against the lip l5. The driving force of the sprocket is therefore transmitted almost directly from the sprocket to the center of the removable tread by the head I3 of the bolt I4.

' What I claim is:

l. In combination with a continuous track for a track laying vehicle made of a helically wound cable the turns of which are held in spaced relation by clamping plates to 'which sprocketl guides are bolted by means of a bolt with a head which protrudes beyond the clamping plates, a shoe with a tread vulcanized to one side thereof, means at each end of the shoe adapted to secure the shoe to the clamping plates and to fasten the clamping plates together, and in the center of the shoe a recess for receiving said bolt head in driv ing relation therewith.

2. In combination with a continuous track for a track laying vehicle made of a helically wound cable the turns of which are held in spaced relationby upper and lower clamping plates spaced at regular intervals along the length thereof with which the sprocket which drives the track contacts and to which sprocket guides are bolted by a bolt, the head of which protrudes below the lower clamping plate, a metal shoe with a rubber tread vulcanized to the lower surface thereof, means for holding each end of each shoe to the clamping plates and a hole in the center of the shoe through which the head of the central I bolt passes in close-fitting relationship thereto.

3. In combination with a continuous track for a track laying vehicle made of helically wound cable ,the turnsY of which are held in spaced relation by upper and lower clamping plates, a shoe with a tread vulcanized tov the lower face and a depression in the upper face into which a projection from the lower clamping plate ts so as to prevent movement of the shoe longitudinally with respect to the track.

4. A continuous track for a track laying vehicle and including endless load-carrying reinforcing means, transversely extending members secured to the reinforcing means at regularly spaced intervals, an endless rubber-like body vulcanized to the reinforcing means and to the transversely extending members, a tread shoe for each transverse member comprising a metal base plate and a rubber-like tread body, means releasably securing-the ends of each tread shoe to the ends of its associated transverse member, a sprocket guide for each transverse member, means securing each sprocket guide to the side of its associated transverse member opposite the tread shoe, means associated with the last-named means and having only a driving engagement with the base plate of the tread shoe, and a surface on each transverse member adapted to have driving engagement with a drive sprocket.

5. A continuous track fora track laying ve hicle and including endless load-carrying reinforcing means, transversely extending members secured to the reinforcing means at regularly spaced intervals, an endless rubber-like body vulcanized to the reinforcing means and to the transversely extending members, a tread shoe for each transverse member comprising a metal base plate and a rubber-like tread body, means releasably securing the ends of each tread shoe to the ends of its associated transverse member, and

means other than lthe last-named means carried by each transverse member and having only ay driving connection with the associated tread shoe.

KARL B. KILBoRN. 

